1 /* 2 * OpenRISC module.c 3 * 4 * Linux architectural port borrowing liberally from similar works of 5 * others. All original copyrights apply as per the original source 6 * declaration. 7 * 8 * Modifications for the OpenRISC architecture: 9 * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se> 10 * 11 * This program is free software; you can redistribute it and/or 12 * modify it under the terms of the GNU General Public License 13 * as published by the Free Software Foundation; either version 14 * 2 of the License, or (at your option) any later version. 15 */ 16 17 #include <linux/moduleloader.h> 18 #include <linux/elf.h> 19 20 int apply_relocate_add(Elf32_Shdr *sechdrs, 21 const char *strtab, 22 unsigned int symindex, 23 unsigned int relsec, 24 struct module *me) 25 { 26 unsigned int i; 27 Elf32_Rela *rel = (void *)sechdrs[relsec].sh_addr; 28 Elf32_Sym *sym; 29 uint32_t *location; 30 uint32_t value; 31 32 pr_debug("Applying relocate section %u to %u\n", relsec, 33 sechdrs[relsec].sh_info); 34 for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) { 35 /* This is where to make the change */ 36 location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr 37 + rel[i].r_offset; 38 39 /* This is the symbol it is referring to. Note that all 40 undefined symbols have been resolved. */ 41 sym = (Elf32_Sym *)sechdrs[symindex].sh_addr 42 + ELF32_R_SYM(rel[i].r_info); 43 value = sym->st_value + rel[i].r_addend; 44 45 switch (ELF32_R_TYPE(rel[i].r_info)) { 46 case R_OR32_32: 47 *location = value; 48 break; 49 case R_OR32_CONST: 50 location = (uint16_t *)location + 1; 51 *((uint16_t *)location) = (uint16_t) (value); 52 break; 53 case R_OR32_CONSTH: 54 location = (uint16_t *)location + 1; 55 *((uint16_t *)location) = (uint16_t) (value >> 16); 56 break; 57 case R_OR32_JUMPTARG: 58 value -= (uint32_t)location; 59 value >>= 2; 60 value &= 0x03ffffff; 61 value |= *location & 0xfc000000; 62 *location = value; 63 break; 64 default: 65 pr_err("module %s: Unknown relocation: %u\n", 66 me->name, ELF32_R_TYPE(rel[i].r_info)); 67 break; 68 } 69 } 70 71 return 0; 72 } 73